The present invention relates to marine drive steering systems and, more particularly, to a demountable retainer for interconnecting key components of the steering linkage.
In both stern drive and outboard marine engines, a commonly utilized steering system includes a cable-driven ram to operate the drive steering arm. In a common arrangement, the ram and steering arm are interconnected by a link rod which includes a short right angled end portion rotatably secured in an aperture at the end of the ram. In an alternate arrangement, the ram and link rod may be interconnected by a lost motion ram link in a similar manner.
Examples of such steering linkage connections are shown in U.S. Pat. Nos. 4,349,341, 4,362,515, 4,416,636 and 4,482,331.
The short right angled end portion of the link rod is generally provided with an annular shoulder and reduced diameter threaded end. The end is inserted through an aperture in the end of the ram (or interposed lost motion ram link) and secured in place with a self-locking nut. The lock nut allows relative rotation in between the parts and is intended to maintain the linkage if the engine is tilted or the linkage is otherwise subjected to a force tending to displace it from its operative position, such as the usual bumping or jarring incurred in the operation of a boat. The loads imposed on the lock nut are, in any event, typically not large and its function is primarily to retain the interconnection of the steering linkage components. In place of the self-locking nut, a nut or other threaded fastener utilizing a cotter pin is also sometimes used.
The steering linkage must occasionally be disconnected, particularly in an outboard motor application when the motor is removed from the boat. The output ram-link arm connection is a convenient point for disconnection.
However, boat owners or operators may not appreciate the locking function provided by the fastening assembly furnished with the original construction. Thus, as a result of subsequent disassembly, the reassembly of the connection may be made improperly. For example, the original self-locking nut may be replaced by a simple non-locking nut or other threaded fastener, or a cotter pin may be left out in the reassembly. In any event, vibration of the improperly reassembled connection can cause the simple threaded fastener to come off and subject the steering linkage to inadvertant disconnection.
Thus, a more fool-proof connection and retaining assembly would be desirable which would preclude the use of improper substitute fasteners. Further, it would also be desirable to have a connection assembly which provides positive retention, but can be assembled and disassembled without the use of tools.